Grow your own Teeth

Grow-your-own to replace false teeth - May 3, 2004

The British institution of dentures sitting in a glass of water beside the bed could be rendered obsolete by scientists who are confident that people will soon be able to replace lost teeth by growing new ones.

Instead of false teeth, a small ball of cells capable of growing into a new tooth will be implanted where the missing one used to be.

The procedure needs only a local anesthetic and the new tooth should be fully formed within a few months of the cells being implanted.

Paul Sharpe, a specialist in the field of regenerative dentistry at the Dental Institute of King's College, London, says the new procedure has distinct advantages over false teeth that require a metal post to be driven into the jaw before being capped with a porcelain or plastic tooth.

"The surgery today can be extensive and you need to have good solid bone in the jaw and that is a major problem for some people," Professor Sharpe said.

The method could be used on far more patients because the ball of cells that grows into a tooth also produces bone that anchors to the jaw.

The choice of growing a new tooth is likely to appeal to patients. "Anyone who has lost teeth will tell you that, given the chance, they would rather have their own teeth than false ones," said Prof Sharpe. The average Briton over 50 has lost 12 teeth from a set of 32.

The procedure is fairly simple. Doctors take stem cells from the patient. These are unique in their ability to form any of the tissues that make up the body. By carefully nurturing the stem cells in a laboratory, scientists can nudge the cells down a path that will make them grow into a tooth. After a couple of weeks, the ball of cells, known as a bud, is ready to be implanted. Tests reveal what type of tooth - for example, a molar or an incisor - the bud will form.

Using a local anesthetic, the tooth bud is inserted through a small incision into the gum. Within months, the cells will have matured into a fully-formed tooth, fused to the jawbone. As the tooth grows, it releases chemicals that encourage nerves and blood vessels to link up with it.

Tests have shown the technique to work in mice, where new teeth took weeks to grow. "There's no reason why it shouldn't work in humans, the principles are the same," said Prof Sharpe.

His team has set up a company, Odontis, to exploit the technique, and has won �400,000 from the National Endowment for Science, Technology and the Arts and the Wellcome Trust.